Table 6.

Auditory–perceptual and acoustic descriptions for eight subtypes of inappropriate between-words pauses.

Type	Subtype	Locus of inappropriate behavior		Descriptions of eight types of inappropriate pauses
		Within pause	Within adjacent sound(s)
Type I	Abrupt		X	A pause immediately preceded or followed by a phoneme that includes a sudden strong onset of energy or sudden offset of energy. Steep-amplitude rise/fall time is the best current visual and acoustic correlate of the percept of an abrupt phoneme.
	Alone	–	–	A pause that occurs at a linguistically incorrect position in an utterance, is not one of the other seven subtypes of inappropriate pauses, and does not have any identifiable auditory or acoustic feature.
	Change		X	A pause immediately preceded or followed by a phoneme or word that includes a significant change in amplitude, frequency, or rate.
	Grope	X		A pause that includes visible acoustic energy in the spectrogram consistent with a lip or tongue gesture or inappropriate voicing. The gestures may include formant traces of sounds or traces of incompletely realized stop bursts.
Type II	Long	X		A pause that has a lengthened duration that is unusual for the linguistic context (usually > 750 ms).
	Breath	X		A pause that includes audible inhalation not associated with excessive length of the utterance or emotional excitement.
	Repetitions/revisions		X	A pause immediately preceded or followed by a dysfluent word or syllable repetition or revision.
	Additions		X	A pause immediately preceded or followed by an added speech sound.

Note. See text for rationale for dividing the subtypes into two classes termed Type I and Type II. The four subtypes of inappropriate pauses within Type I and within Type II are each listed in decreasing frequency of occurrence in the present sample of participants with childhood apraxia of speech.